Recent Advances in Rechargeable Metal–CO₂ Batteries with Nonaqueous Electrolytes

Abstract

This review article discusses the recent advances in rechargeable metal–CO2 batteries (MCBs), which include the Li, Na, K, Mg, and Al-based rechargeable CO2 batteries, mainly with nonaqueous electrolytes. MCBs capture CO2 during discharge by the CO2 reduction reaction and release it during charging by the CO2 evolution reaction. MCBs are recognized as one of the most sophisticated artificial modes for CO2 fixation by electrical energy generation. However, extensive research and substantial developments are required before MCBs appear as reliable, sustainable, and safe energy storage systems. The rechargeable MCBs suffer from the hindrances like huge charging–discharging overpotential and poor cyclability due to the incomplete decomposition and piling of the insulating and chemically stable compounds, mainly carbonates. Efficient cathode catalysts and a suitable architectural design of the cathode catalysts are essential to address this issue. Besides, electrolytes also play a vital role in safety, ionic transportation, stable solid-electrolyte interphase formation, gas dissolution, leakage, corrosion, operational voltage window, etc. The highly electrochemically active metals like Li, Na, and K anodes severely suffer from parasitic reactions and dendrite formation. Recent research works on the aforementioned secondary MCBs have been categorically reviewed here, portraying the latest findings on the key aspects governing secondary MCB performances.

Toward Practical Li–CO2 Batteries: Mechanisms, Catalysts, and Perspectives

“…Varieties of CCU technologies of thermocatalytic, electrocatalytic, photocatalytic, and photoelectrocatalytic reduction have been developed. − In these processes, CO 2 is transformed into value-added carbonaceous chemicals, and thermal, electrical, or/and solar energy is stored as chemical energy. Due to the dual functions of CO 2 conversion and electrical energy supply, metal–CO 2 batteries that have emerged in the past decade provide an attractive option for achieving the target of carbon neutrality. − Up to now, metal–CO 2 batteries reported mainly include Li–CO 2 , Na–CO 2 , K–CO 2 , Mg–CO 2 , Al–CO 2 , and Zn–CO 2 ones. On the basis of their different application scenarios for energy storage and chemical production, these metal–CO 2 batteries can be roughly classified as nonaqueous and aqueous electrolyte-based systems. , As schemed in Figure a, typically, a nonaqueous electrolyte-based metal–CO 2 battery contains a metal anode (Li, Na, K, Mg, or Al), an electrolyte-soaked separator, and a porous cathode that can breathe CO 2 .…”

“…These systems perform more resemble electrocatalytic CO 2 reduction, in which CO 2 is reduced to carbonaceous compounds on cathodes, such as CO, HCOOH, C 2 H 4 , etc. Critical electrochemical parameters and major anodic/cathodic reactions of metal–CO 2 batteries are summarized in Table . ,, Li–CO 2 batteries show the highest cell potential of 2.80 V and the largest theoretical specific energy of 1880 Wh kg –1 owing to the lowest standard reduction potential (−3.04 V vs SHE) and the largest theoretical specific capacity (3861 mAh g –1 ) of Li (Figure c and Table ). These advantages over other systems make the development of practical Li–CO 2 batteries highly attractive. Anode : M ↔ M n + + n e − Cathode : x M n + + 3 n x 4 CO 2 + n x e − ↔ x 2 M 2 false( normalC normalO 3 false) n + n x 4 C …”

“… a (1) Critical electrochemical parameters and anodic/cathodic reactions of Li, Na, K, Mg, and Al–CO 2 batteries are obtained from ref . (2) Standard reduction potential of the Zn anode and anodic/cathodic reactions of the Zn–CO 2 battery are obtained from ref .…”

Anode-less Hybrid Na–CO2 Battery with Sodium Harvesting from Seawater for Both Electricity Storage and Various Chemical Production

“…Therefore, many review papers emphasize the importance of designing a system that can address these challenges. [9][10][11]15,17,22 A hybrid Na−CO 2 battery maintains an attractive prospect for practical energy storage with high energy density by utilizing the high driving force (low redox potential, E Na + /Na of −2.7 V vs SHE) of Na. 23 However, previous studies on hybrid Na−CO 2 batteries have been limited in their ability to produce high-value-added products because they only produce Na 2 CO 3 as a discharge product.…”

“…Although Zn–CO 2 batteries show the possibility of integrated devices for electricity storage and CO 2 conversion into useful products, they have a low energy density and are limited to producing only C 1 chemicals during discharge. Therefore, many review papers emphasize the importance of designing a system that can address these challenges. − ,,, …”